Choose AionLabs: Aion 3.5 if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
AionLabs: Aion 3.5 vs Tencent: Hy4 preview
Tencent: Hy4 preview comes out ahead on the data we track: 4 advantages and none for AionLabs: Aion 3.5.
Key numbers
| Spec | AionLabs: Aion 3.5 | Tencent: Hy4 preview |
|---|---|---|
| Provider | Aion Labs | Tencent |
| Input price (per 1M tokens) | $3.00 | $0.83 |
| Output price (per 1M tokens) | $6.00 | $2.50 |
| Blended price (3:1 input/output) | $3.75 | $1.25 |
| Cheaper than … of all models we track | 17% | 35% |
| Context window | 262K tokens (~393 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 48% | 81% |
| Max output per response | 33K tokens (~24,600 words) | 64K tokens (~48,000 words) |
| Input types | text | text |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-09-23 | 2026-08-28 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | AionLabs: Aion 3.5 | Tencent: Hy4 preview | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $345 | $113 | Tencent: Hy4 preview saves $232 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $420 | $125 | Tencent: Hy4 preview saves $295 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $432 | $130 | Tencent: Hy4 preview saves $302 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $276 | $81.73 | Tencent: Hy4 preview saves $194 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $156 | $44.20 | Tencent: Hy4 preview saves $112 |
Capabilities side by side
| Capability | AionLabs: Aion 3.5 | Tencent: Hy4 preview | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | — | — | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | — | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- AionLabs: Aion 3.5: price unchanged since we started tracking it on 2026-09-24.
- Tencent: Hy4 preview: price unchanged since we started tracking it on 2026-08-29.
Which should you choose?
Choose Tencent: Hy4 preview if…
- cost matters at scale — it is 67% cheaper on a typical 3:1 input/output mix ($113 vs $345 a month for 50,000 support chats)
- you need to fit long inputs in one request — 1.0M tokens is roughly 1,573 pages, against 393
- you need seed (reproducible sampling) — to repeat a generation for tests and evals; AionLabs: Aion 3.5 does not advertise it
- you generate long outputs in one go — up to 64K tokens (about 48,000 words) per response
Frequently asked questions
Is AionLabs: Aion 3.5 better than Tencent: Hy4 preview?
Tencent: Hy4 preview comes out ahead on the data we track: 4 advantages and none for AionLabs: Aion 3.5.
Which is cheaper, AionLabs: Aion 3.5 or Tencent: Hy4 preview?
Tencent: Hy4 preview is cheaper: $1.25 vs $3.75 per 1M tokens at a typical 3:1 input/output mix, 67% less. For 50,000 support conversations a month that is $113 against $345.
How much do AionLabs: Aion 3.5 and Tencent: Hy4 preview cost per million tokens?
AionLabs: Aion 3.5 costs $3.00 per 1M input tokens and $6.00 per 1M output tokens; Tencent: Hy4 preview costs $0.83 input and $2.50 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AionLabs: Aion 3.5 or Tencent: Hy4 preview?
Tencent: Hy4 preview: 1.0M tokens, about 1,573 pages, against 262K (about 393 pages) for AionLabs: Aion 3.5.
Do AionLabs: Aion 3.5 and Tencent: Hy4 preview support function calling and JSON output?
Tool calling — AionLabs: Aion 3.5: yes, Tencent: Hy4 preview: yes. JSON-schema structured output — AionLabs: Aion 3.5: yes, Tencent: Hy4 preview: yes.
Can AionLabs: Aion 3.5 or Tencent: Hy4 preview read images?
Neither accepts image input — both are text-in models.
Is AionLabs: Aion 3.5 or Tencent: Hy4 preview free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of AionLabs: Aion 3.5 and Tencent: Hy4 preview?
AionLabs: Aion 3.5 can write up to 33K tokens (about 24,600 words) per response; Tencent: Hy4 preview up to 64K (about 48,000 words).
When were AionLabs: Aion 3.5 and Tencent: Hy4 preview released?
AionLabs: Aion 3.5 was listed on 2026-09-23; Tencent: Hy4 preview on 2026-08-28.
About the two models
AionLabs: Aion 3.5
Aion 3.5 is a multi-model roleplaying and storytelling system from AionLabs, built on the GLM family of models. It uses a collaborative generation process in which multiple specialized models each...
Full AionLabs: Aion 3.5 specs →Tencent: Hy4 preview
Tencent: Hy4 preview is a mixture-of-experts model from Tencent, with 49B active parameters out of 770B total. It is designed for coding agents, complex tool-use workflows, and productivity tasks that...
Full Tencent: Hy4 preview specs →